Abstract
A long-term, 15-year nitrogen (N) fertilization trial was carried out in Rheingau, Germany. While the control received no N, the fertilized treatments received 30, 60, or 90 kg N/ha. Treatments used in this investigation were 0/0, 30/0, 0/30, 60/0, 30/30, 0/60, 90/0, 60/30, and 30/60 (application of N/ha at budbreak/application of N/ha at fruit set). Fertilization at budbreak resulted in a peak of NO3 in the soil at fruit set; when N was applied at fruit set, the highest amounts of NO3 were found at veraison. Average NO3 concentration in the soil also increased with budbreak fertilization compared with fruit-set fertilization. Leaf analysis showed an increased N uptake with budbreak fertilization of 90 kg N/ha. Grape yield showed a reverse timing effect: earlier fertilization at budbreak resulted in lower yield. The same observation was made for total soluble solids when grapes were fertilized with 60 or 90 kg N/ha. The storage of Mg and Ca in grapes was increased by fruit-set fertilization compared with budbreak fertilization; in the highly fertilized treatment that was also true for N in must.
- Received May 2007.
- Revision received December 2007.
- Revision received March 2008.
- Copyright © 2008 by the American Society for Enology and Viticulture
Sign in for ASEV members
ASEV Members, please sign in at ASEV to access the journal online.
Sign in for Institutional and Non-member Subscribers
Log in using your username and password
Pay Per Article - You may access this article (from the computer you are currently using) for 2 day for US$10.00
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.